Here in TN, I have a garage, I average about 19 so far this winter. I have 3.73s, auto and a 4.0 OHV. It's been around 25 so far. I start her and go.

In Montana I got about 10, because you had to let the thing warm up before you went anywhere! it would get about 40 below zero and my transmission would whine like a howler monkey till I put a pan heater in her. I would let her warm up a good 20 minutes if I didn't plug it in, then I had to start her and warm her up when I went to work overnight or I wasn't getting anywhere fast.